Embodiments of the present invention relate to a heat exchanger.
Published Japanese Translation of PCT International Application No. 2001-525051 discloses a conventional heat exchanger 50. In FIGS. 1 to 5, the lateral, longitudinal and height directions of the heat exchanger 50 are defined as X, Y and Z axes, respectively. The X, Y and Z axes are orthogonal to one another. As shown in FIG. 1, the heat exchanger 50 includes tubes 51, corrugated fins 52, a pair of header pipes 53, an inlet manifold 54, an outlet manifold 55, and a pair of blocking caps 56. The plurality of tubes 51 are arranged along the X axis mutually in parallel and at even intervals. Each of the plurality of corrugated fins 52 is disposed between two adjacent tubes 51. The pair of header pipes 53 house both ends of the plurality of tubes 51. The inlet manifold 54 is fixed to one end of one of the header pipes 53 on a −X side. The outlet manifold 55 is fixed to one end of the other header pipe 53 on a +X side. The pair of blocking caps 56 block the respective other ends of the pair of header pipes 53.
The heat exchanger 50 causes a first fluid flowing in from the inlet manifold 54 to circulate along a given passage formed by the header pipes 53 and the tubes 51. In the heat exchanger 50, heat exchange takes place efficiently between the first fluid passing inside the tubes 51 and a second fluid passing outside the tubes 51.
In the heat exchanger 50, as shown in FIGS. 2 and 3, four parallel fluid circulation holes 57 are formed inside each header pipe 53 along a longitudinal direction of the header pipe 53. A plurality of parallel tube insertion holes 58 are formed along a lateral direction of the header pipe 53. The fluid circulation holes 57 and the tube insertion holes 58 are orthogonal to one another. One end of each of the tube insertion holes 58 penetrates through an outer side surface 53a of the associated header pipe 53 and opens to the outside thereof. Both end portions of the tubes 51 are inserted into the tube insertion holes 58 and are fixed to the header pipes 53 by brazing or the like.
As shown in FIG. 4, at an upper end portion of the header pipe 53 on the −X side, the fluid circulation holes 57 open to an inlet hole 54a of the inlet manifold 54. In order to connect the header pipe 53 on the −X side to the inlet manifold 54, a manifold side connection hole 54b, which has the same shape as the upper end portion of the header pipe 53 on the −X side, is formed on a lower surface of the inlet manifold 54. The upper end portion of the header pipe 53 on the −X side is inserted into the manifold side connection hole 54b of the inlet manifold 54 and is fixed to the inlet manifold 54 by brazing or the like. Moreover, the header pipes 53 are fixed to the outlet manifold 55 and the blocking caps 56 in a similar manner.
When the heat exchanger 50 is manufactured as previously described, in order to insert the upper end portion of the header pipe 53 on the −X side directly into the inlet manifold 54, the manifold side connection hole 54b (which has the same shape as the upper end portion of the header pipe 53 on the −X side) is formed on the lower surface of the inlet manifold 54. Therefore, as shown in FIG. 5, in a cross section parallel to an X-Y plane, the area of the inlet manifold 54 is greater than the area of the upper end portion of the header pipe 53 on the −X side. Similarly, manifold side connection holes (not shown), which have the same shapes as the end portions of the header pipes 53, are also formed on the outlet manifold 55 and the blocking caps 56. Accordingly, in the cross section parallel to the X-Y plane, the areas of the outlet manifold 55 and the blocking caps 56 are each greater than the areas of the respective end portions of the header pipes 53. Therefore, the inlet manifold 54, the outlet manifold 55, and the blocking caps 56 are each larger than the respective end portions of the header pipes 53, thereby increasing the size of the heat exchanger 50 and correspondingly impairing the ease by which the heat exchanger 50 is handled.